U.S. patent application Ser. No. 15/582,545, filed Apr. 28, 2017, naming Ali Hormati and Richard Simpson, entitled “Clock Data Recovery with Decision Feedback Equalization” hereinafter identified as [Hormati II].

In communication systems, a goal is to transport information from one physical location to another. One common information transfer medium is the serial communications link, which may be based on a single wire circuit relative to ground or other common reference, multiple such circuits relative to ground or other common reference, or multiple circuits used in relation to each other. A common example of the latter uses differential signaling (“DS”). Differential signaling operates by sending a signal on one wire and the opposite of that signal on a matching wire. The signal information is represented by the difference between the wires, rather than their absolute values relative to ground or other fixed reference. Vector signaling is another such example. With vector signaling, a plurality of signals on a plurality of wires are considered collectively, although each of the plurality of signals might be independent. With binary vector signaling, each component or “symbol” of the vector takes on one of two possible values. With non-binary vector signaling, each symbol has a value that is a selection from a set of more than two possible values. Any suitable subset of a vector signaling code denotes a “subcode” of that code. Such a subcode may itself be a vector signaling code.